An air ambulance helicopter crashed into a wooded area of Arkansas early Tuesday, killing all three crewmembers and raising the death toll in the industry to 22 in the past year.

The Air Evac Lifeteam chopper was flying to pick up a victim of a traffic accident when it hit trees and crashed, bursting into flames about 4:30 a.m., Federal Aviation Administration (FAA) spokesman Lynn Lunsford said. The pilot and two medical crewmembers died, he said.

The crash, near the town of Scotland, is the latest in a surge of accidents and fatalities. The past year has seen 14 accidents involving air ambulance helicopters, eight fatal, government statistics show. Since June, four crashes have killed 10 people.

Advocates for safety improvements said the crash is further evidence of the need for stiff new requirements on medevac flights.

"There is a long way to go and we're not there yet," said Stacey Friedman, whose sister, flight nurse Erin Reed, died in a 2005 crash.

The National Transportation Safety Board (NTSB), which is heading the investigation into Tuesday's crash, has issued numerous suggested safety improvements for the industry in recent years. The agency has no regulatory authority. The FAA, which oversees the industry, is writing new rules but will not unveil them until fall. Congress has several bills addressing safety, but those have stalled in a deadlock over FAA's funding.

Dan Hankins, a physician who directs a hospital air-ambulance program and is president of the Association of Air Medical Services, said he supports adoption of the NTSB's recommendations. However, he acknowledged that not all of the companies in his organization back the recommendations.

The NTSB wants new requirements for equipment that can help prevent pilots from getting disoriented in poor visibility, better pilot training and improved internal monitoring for safety lapses.